Which is a counterexample to the conjecture?
any number that is divisible by 3 is divisible by 9.
63
69
18
27

From the bottom up:

-- Is 27 a counter example ?  No.  It's divisible by 3 and also by 9 .

-- Is 18 a counter example ?  No.  It's divisible by 3 and also by 9 .

-- Is 69 a counter example ?  Yes !  It's divisible by 3, but not by 9 .

-- Is 63 a counter example ?  No.  It's divisible by 3 and also by 9 .

Your answer would be ahere is how: perimeter is how long all the sides are. in a rectangle, there are two sets of parallel sides. so, to find this, we would to the following.(15x2)+(4x2)30+838if you have questions ask! and mark me brainliest! i really wanna level up : 3